Hierarchical display and navigation of document revision histories

ABSTRACT

A system and technique for displaying a document&#39;s workflow history are disclosed. The system includes a graphical user interface for displaying one or more graphical representations of events generated by an application configured to edit a document. Each of the events generated by the application may be stored in a data structure that is associated with one or more portions of the document. The data structure may also be associated with a digital image that reflects the state of the document at the time the event was generated and one or more frames of digital video captured substantially simultaneously with the generation of the event. The system may display the stored events via graphical representations in the graphical user interface that represent a portion of the total document workflow history. A user may navigate through the graphical events based on a hierarchical algorithm for clustering events.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to computer software and, morespecifically, to the hierarchical display and navigation of documentrevision histories.

2. Description of the Related Art

Users create documents in a variety of different applications, such asword processors, spreadsheets, image editors, and computer-aided design(CAD) applications. A revision history of a document is typicallythought of as the set of ordered operations a user has performed in theapplication to create or modify contents of the document. One usefulaspect of a revision history is the ability to undo, redo, or modify anoperation that is stored in the revision history. Some applicationsdiscard a revision history when the document is either saved or closed,while other applications store the revision history along with thedocument. A revision history is typically visualized or navigated usingone of many available techniques, such as textual lists, instructionspresented in natural language, enhanced screen shots, before-and-afterthumbnails, animations or videos.

One drawback to an approach for displaying a document revision historyimplemented by many applications is that user operations are not groupedbased on a hierarchical system. For complex applications, the number ofuser operations stored in a revision history can become quite large.Typically, each of the user operations is displayed in a similar mannerto all other user operations and navigating through all the useroperations may become difficult. Another drawback of many applicationsthat store a revision history of a document is that the ability toutilize the information stored for a user operation may be limited. Forexample, in some applications, operations based on the document revisionhistory may be limited to undoing the last user operation. Yet anotherdrawback to current approaches for displaying a document revisionhistory is that, for example, simply listing the document revisionhistory may not provide a user with enough information to understand whya series of revisions were made, but merely informs the user whichrevisions resulted in the final document.

As the foregoing illustrates, what is needed in the art is an effectivemechanism for displaying, navigating and interacting with informationstored in a complete revision history of a document.

SUMMARY OF THE INVENTION

One example embodiment of the present invention sets forth a method forgenerating and navigating a graphical representation of a workflowhistory of an electronic document. The method includes the steps ofaccessing a plurality of data objects stored in a memory, where eachdata object stores information related to a different event generated byan application that is configured to modify the document, identifying afirst time and a second time during which the application generatesevents, selecting a set of data objects from the plurality of dataobjects, where each data object in the set of data objects includes atimestamp reflecting a time that is equal to either the first time orequal to the second time or falls in between the first time and thesecond time, generating a graphical representation of the set of dataobjects, and causing the graphical representation to be displayed in agraphical user interface associated with the application.

Another example embodiment of the present invention sets forth acomputer readable storage medium containing a program which, whenexecuted, performs an operation for generating and navigating agraphical representation of a workflow history of an electronicdocument. The operation includes the steps of accessing a plurality ofdata objects stored in a memory, where each data object storesinformation related to a different event generated by an applicationthat is configured to modify the document, identifying a first time anda second time during which the application generates events, selecting aset of data objects from the plurality of data objects, where each dataobject in the set of data objects includes a timestamp reflecting a timethat is equal to either the first time or equal to the second time orfalls in between the first time and the second time, generating agraphical representation of the set of data objects, and causing thegraphical representation to be displayed in a graphical user interfaceassociated with the application.

Yet another example embodiment of the present invention sets forth asystem for capturing a workflow history of an electronic document. Thesystem includes a memory and a processor coupled to the memory andconfigured to access a plurality of data objects stored in a memory,where each data object stores information related to a different eventgenerated by an application that is configured to modify the document,identify a first time and a second time during which the applicationgenerates events, select a set of data objects from the plurality ofdata objects, where each data object in the set of data objects includesa timestamp reflecting a time that is equal to either the first time orequal to the second time or falls in between the first time and thesecond time, generate a graphical representation of the set of dataobjects, and cause the graphical representation to be displayed in agraphical user interface associated with the application.

One advantage of the disclosed approach is that the system provides aflexible and intuitive approach for displaying and navigating therevision history of a document. Even a large revision history thatincludes hundreds of user operations may be reduced to a simplegraphical representation that may be navigated by a user to visualizethe revision history at finer and finer detail. A user may use toolswithin the system to filter or search the revision history forparticular types of user operations. The hierarchical, high-levelclustering algorithm also presents each of the user operations withinthe context of the complete revision history, allowing a user tovisualize and learn various techniques for creating or modifying thecontent of a document. In addition, captured video content associatedwith the revision history may be played back to provide the user contextwithin the application of how a document was revised.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the inventioncan be understood in detail, a more particular description of theinvention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a block diagram of a system configured to implement one ormore aspects of the present invention;

FIG. 2 illustrates a conceptual diagram of an application framework forgenerating and displaying document workflow histories, according to oneembodiment of the present invention;

FIGS. 3A-3C illustrate a graphical user interface associated with theapplication framework of FIG. 2, according to one embodiment of thepresent invention;

FIGS. 4A-4C illustrate the generation of data objects in event databased on events generated by application, according to one exampleembodiment of the present invention;

FIG. 5 illustrates a graphical user interface displayed in the hostapplication window, according to one example embodiment of the presentinvention;

FIGS. 6A-6B illustrate the document workflow window, according to oneexample embodiment of the present invention;

FIGS. 7A-7B illustrate the data probe, according to one exampleembodiment of the present invention;

FIG. 8 illustrates the user interface probe, according to one exampleembodiment of the present invention;

FIG. 9 illustrates the selection probe, according to one exampleembodiment of the present invention;

FIG. 10 illustrates a timeline window, according to one exampleembodiment of the present invention;

FIG. 11 illustrates a graphical user interface for a calendar view ofthe document workflow history, according to one example embodiment ofthe present invention;

FIGS. 12A-12B illustrate adding annotations to one or more frames ofvideo data, according to one example embodiment of the presentinvention;

FIG. 13 is a flowchart of method steps for capturing a workflow historyof an electronic document, according to one example embodiment of thepresent invention;

FIG. 14 is a flowchart of method steps for generating and navigating agraphical representation of a workflow history of an electronicdocument, according to one example embodiment of the present invention;

FIG. 15 is a flowchart of method steps for generating and displayingvideo data representing a workflow history of an electronic document,according to one example embodiment of the present invention;

FIG. 16 is a flowchart of method steps for configuring an applicationbased on a workflow history of an electronic document, according to oneexample embodiment of the present invention; and

FIG. 17 is a flowchart of method steps for displaying a workflow historyof a document, according to one example embodiment of the presentinvention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a more thorough understanding of the invention. However, it willbe apparent to one of skill in the art that the invention may bepracticed without one or more of these specific details. In otherinstances, well-known features have not been described in order to avoidobscuring the invention.

System Overview

FIG. 1 is a block diagram of a system 100 configured to implement one ormore aspects of the present invention. System 100 may be a computerworkstation, personal computer, or any other device suitable forpracticing one or more embodiments of the present invention. As shown,system 100 includes one or more processing units, such as centralprocessing unit (CPU) 102, and a system memory 104 communicating via abus path that may include a memory bridge 105. CPU 102 includes one ormore processing cores, and, in operation, CPU 102 is the masterprocessor of system 100, controlling and coordinating operations ofother system components. System memory 104 stores software applicationsand data for use by CPU 102. CPU 102 runs software applications andoptionally an operating system. Memory bridge 105, which may be, e.g., aNorthbridge chip, is connected via a bus or other communication path(e.g., a HyperTransport link) to an I/O (input/output) bridge 107. I/Obridge 107, which may be, e.g., a Southbridge chip, receives user inputfrom one or more user input devices such as keyboard 108 or mouse 109and forwards the input to CPU 102 via memory bridge 105. In alternativeembodiments, I/O bridge 107 may also be connected to other input devicessuch as a joystick, digitizer tablets, touch pads, touch screens, stillor video cameras, motion sensors, and/or microphones (not shown).

One or more display processors, such as display processor 112, arecoupled to memory bridge 105 via a bus or other communication path 113(e.g., a PCI Express, Accelerated Graphics Port, or HyperTransportlink); in one embodiment display processor 112 is a graphics subsystemthat includes at least one graphics processing unit (GPU) and graphicsmemory. Graphics memory includes a display memory (e.g., a frame buffer)used for storing pixel data for each pixel of an output image. Graphicsmemory can be integrated in the same device as the GPU, connected as aseparate device with the GPU, and/or implemented within system memory104. Display processor 112 periodically delivers pixels to a displaydevice 110 that may be any conventional CRT or LED monitor. Displayprocessor 112 can provide display device 110 with an analog or digitalsignal.

A system disk 114 is also connected to I/O bridge 107 and may beconfigured to store content and applications and data for use by CPU 102and display processor 112. System disk 114 provides non-volatile storagefor applications and data and may include fixed or removable hard diskdrives, flash memory devices, and CD-ROM, DVD-ROM, Blu-ray, HD-DVD, orother magnetic, optical, or solid state storage devices.

A switch 116 provides connections between I/O bridge 107 and othercomponents such as a network adapter 118 and various add-in cards 120and 121. Network adapter 118 allows system 100 to communicate with othersystems via an electronic communications network, and may include wiredor wireless communication over local area networks and wide areanetworks such as the Internet.

Other components (not shown), including USB or other port connections,film recording devices, and the like, may also be connected to I/Obridge 107. For example, an audio processor may be used to generateanalog or digital audio output from instructions and/or data provided byCPU 102, system memory 104, or system disk 114. Communication pathsinterconnecting the various components in FIG. 1 may be implementedusing any suitable protocols, such as PCI (Peripheral ComponentInterconnect), PCI Express (PCI-E), AGP (Accelerated Graphics Port),HyperTransport, or any other bus or point-to-point communicationprotocol(s), and connections between different devices may use differentprotocols, as is known in the art.

In one embodiment, display processor 112 incorporates circuitryoptimized for graphics and video processing, including, for example,video output circuitry, and constitutes a graphics processing unit(GPU). In another embodiment, display processor 112 incorporatescircuitry optimized for general purpose processing. In yet anotherembodiment, display processor 112 may be integrated with one or moreother system elements, such as the memory bridge 105, CPU 102, and I/Obridge 107 to form a system on chip (SoC). In still further embodiments,display processor 112 is omitted and software executed by CPU 102performs the functions of display processor 112.

Pixel data can be provided to display processor 112 directly from CPU102. In some embodiments of the present invention, instructions and/ordata representing a scene are provided to a render farm or a set ofserver computers, each similar to system 100, via network adapter 118 orsystem disk 114. The render farm generates one or more rendered imagesof the scene using the provided instructions and/or data. These renderedimages may be stored on computer-readable media in a digital format andoptionally returned to system 100 for display.

Alternatively, CPU 102 provides display processor 112 with data and/orinstructions defining the desired output images, from which displayprocessor 112 generates the pixel data of one or more output images,including characterizing and/or adjusting the offset between stereoimage pairs. The data and/or instructions defining the desired outputimages can be stored in system memory 104 or a graphics memory withindisplay processor 112. In an embodiment, display processor 112 includes3D rendering capabilities for generating pixel data for output imagesfrom instructions and data defining the geometry, lighting shading,texturing, motion, and/or camera parameters for a scene. Displayprocessor 112 can further include one or more programmable executionunits capable of executing shader programs, tone mapping programs, andthe like.

In one embodiment, application 150 is stored in system memory 104.Application 150 may be any application configured to display a graphicaluser interface (GUI) on display device 110. Application 150 may beconfigured to generate and modify documents based on input received froma user. For example, application 150 may be a word processingapplication or an image editing program.

It will be appreciated that the system shown herein is illustrative andthat variations and modifications are possible. The connection topology,including the number and arrangement of bridges, may be modified asdesired. For instance, in some embodiments, system memory 104 may beconnected to CPU 102 directly rather than through a bridge, and otherdevices may communicate with system memory 104 via memory bridge 105 andCPU 102. In other alternative topologies display processor 112 may beconnected to I/O bridge 107 or directly to CPU 102, rather than tomemory bridge 105. In still other embodiments, I/O bridge 107 and memorybridge 105 may be integrated in a single chip. In addition, theparticular components shown herein are optional. For instance, anynumber of add-in cards or peripheral devices might be supported. In someembodiments, switch 116 is eliminated, and network adapter 118 andadd-in cards 120, 121 connect directly to I/O bridge 107.

FIG. 2 illustrates a conceptual diagram of an application framework 200for generating and displaying document workflow histories, according toone embodiment of the present invention. As shown, computer system 100includes application 210 that is a modified version of application 150that is configured to interface with a document workflow applicationextension 220. For example, application 210 may be based on thePaint.NET application (i.e., an open-source raster based image editingapplication written in the C# programming language). In one embodiment,application 210 is designed to transmit messages to the documentworkflow application extension 220 whenever an event is generated, suchas when a user makes a change to an image or changes one or moresettings in a dialog box. The message may contain information related tothe event such as a timestamp or a screenshot of the application windowat a time corresponding to the generation of the event. In anotherembodiment, application 210 may store a list of events internally andthe document workflow application extension 220 may be configured topoll application 210 to retrieve information related to the list ofevents. It will be appreciated that application 210 may be modified inone or more other technically feasible ways in order to provide thespecific functionality necessary to implement one or more aspects of thepresent invention, as described below. In yet another embodiment, a usermay be able to control, explicitly, whether the document workflowapplication extension 220 monitors events generated by application 210.In this manner, a revision history for a document may containinformation about only a particular portion of the document's life.

Application 210 may be designed to generate and edit documents, images,videos, or any other type of user defined content. A user may generatedocument 215 via application 210 and store document 215 in system memory104 or on system disk 114. In one embodiment, document 215 is an imagestored in a compressed file format, such as the JPEG image file format.In alternative embodiments, document 215 may be a text document, such asa Microsoft Word™ document file. In other embodiments, document 215 maybe media content such as a video file compressed using an MPEG codec. Inyet other embodiments, document 215 may be a computer-aided design (CAD)model. The CAD model may be an assembly of one or more parts thatinclude defined volumes, surfaces or vertices. The application framework200 is configured to capture and store the document workflow history(i.e., document revision history) for one or more documents created ormodified with application 210.

In one embodiment, the document workflow history may include one or moreoperations used to modify document 215 as well as a timestamp thatreflects a point in time that the operations were executed. The documentworkflow history may also include digital images or digital video thatreflects a state of the document 215 as a result of executing theoperations. A user may navigate through graphical representations of thedocument workflow history to visualize the steps taken to create theassociated document 215. In another embodiment, the document workflowhistory may include a subset of operations that directly result in amodification to document 215.

Document workflow application extension 220 may implement an applicationprogramming interface (API). The document workflow application extension220 receives notifications of events generated by application 210 andstores the events in a data object in event data 221. In one embodiment,document workflow application extension 220 generates an data object inevent data 221 for each event generated by application 210. The dataobject in event data 221 may include information related to the event aswell as a timestamp corresponding to when that particular event wasgenerated by the application 210. The timestamp may be an absolute time,such as a time related to the computer clock of computer system 100, ora relative time, such as an elapsed time since document 215 was created.

Document workflow application extension 220 may also be configured tocapture a screenshot (i.e., a digital image) of the main applicationwindow when an event is generated. These screenshots may be stored inimage data 222 and may be associated with one or more data objects inevent data 221. In one embodiment, each screenshot is stored in acompressed file format such as a JPEG file format. In alternativeembodiments, the bit depth of the captured image may be reduced tominimize the size of the memory required to store image data 222. Forexample, the screen resolution of display device 110 in the nativeapplication environment may be 800×600 at 24 bpp (bits per pixel). Sucha resolution corresponds to each color component (e.g., Red, Green, andBlue) being encoded with 8 bits. In contrast, the screenshot may bestored in a 16 bpp color depth such as by using a 565 mode where the redand blue channels are each encoded with 5 bits and the green channel isencoded with 6 bits. Using a reduced color depth to store image data 222may reduce the memory requirements of system 100. In another embodiment,metadata associated with the screenshot may be stored along with thescreenshot in image data 222. Such metadata may be included in thedigital image file and may identify one or more data objects in eventdata 221 associated with the screenshot.

Document workflow application extension 220 may also be configured tocapture video data 223 associated with the document 215. For example,document workflow application extension 220 could be configured tocapture one or more frames of digital video that, when played back,display a dynamic state of document 215 during the generation of theevents stored in the document workflow history. In one embodiment,document workflow application extension 220 may capture a plurality ofscreenshots of the main application window of application 210 at a framerate of 10 frames per second. Each screenshot corresponds to one frameof video data 223. Document workflow application extension 220 may storevideo data 223 in a lossless video format or a compressed format such asby encoding video data 223 using an MPEG-2 video encoder or anH.264/MPEG-4 Advanced Video Coding (AVC) encoder.

In one embodiment, a file header of a document 215 will be modified bythe document workflow application extension 220 when a document revisionhistory has been created by the document workflow application extension220. The document 215 header may include a tag in the header thatspecifies that a document workflow history associated with the documentis stored in a memory and include pointers to any associated metadatasuch as event data 221, image data 222, or video data 223 that areincluded in the document workflow history.

In one embodiment, application 210 and document workflow applicationextension 220 are separate processes executing in a multitaskingoperating system environment on CPU 102. In another embodiment,application 210 and document workflow application extension 220 may beincluded within a single process executing on CPU 102. Application 210,document 215, document workflow application extension 220, event data221, image data 222, and video data 223 may all be stored locally insystem memory 104 during execution. It will be appreciated that in someembodiments, document 215, event data 221, image data 222, and videodata 223 may be written to system disk 114 or other non-volatile storageconnected to computer system 100 and paged into system memory 104 asneeded. Alternatively, such data may be stored remotely on a serverlocated on the Internet and accessed remotely via network adapter 118.

In one embodiment, a user may use the document workflow applicationextension 220 to search stored document revision histories for aplurality of saved documents 215. For example, a user may be interestedin finding other documents 215 that include a revision made with aspecific tool, such as a line tool. A user may submit a query to thedocument workflow application extension 220 which then searches throughmultiple sets of event data 221 associated with different documents 215and returns a subset of documents 215 that include an entry in eventdata 221 related to the line tool. In this way, a user may quicklysearch through a database of documents 215 to find examples of workrelated to specific tools of the application 210.

FIGS. 3A-3C illustrate a graphical user interface 300 associated withthe application framework 200 of FIG. 2, according to one embodiment ofthe present invention. As shown in FIG. 3A, application 210 causes ahost application window 310 to be displayed on display device 110. Thehost application window 310 may provide a user with a GUI that providesfunctionality to generate or modify the contents of document 215. Forexample, the GUI may include menus, toolbars, a document frame, and oneor more dialog boxes. In one embodiment, the host application window 310includes a document frame that displays a single document to be modifiedby a user. In alternative embodiments, host application window 310 maybe configured to display two or more documents 215 simultaneously in twoor more child frames (not shown) within the host application window 310such that a user may modify multiple documents 215 substantiallysimultaneously. A screenshot of host application window 310, accordingto one embodiment of the present invention, is described below inconnection with FIG. 5.

In one embodiment, document workflow application extension 220 may beexecuting as a process in the background of computer system 100 while auser is generating or modifying document 215 via application 210.Document workflow application extension 220 is configured to storeinformation related to events in event data 221 in order to capture thedocument workflow history of document 215. Document workflow applicationextension 220 generates data objects in event data 221, storesscreenshots of host application window 310 in image data 222, and storesone or more frames of digital video in video data 223 as well ascreating associations between the data objects in event data 221, thescreenshots in image data 222, and the frames of digital video in videodata 223. For example, document workflow application extension 220 maystore metadata along with a screenshot in image data 222 that associatesthe screenshot with a data object in event data 221. More detailedinformation about the generation and storage of event data 221, imagedata 222, and video data 223 is set forth below in conjunction with adescription of FIG. 4.

Document workflow application extension 220 may enable a user to viewthe document workflow history in a hierarchical, graphicalrepresentation. In one embodiment, a GUI associated with documentworkflow application extension 220 may be displayed on display device110 in response to a user command. In another embodiment, the GUIassociated with the document workflow application extension 220 may bedisplayed automatically whenever a document 215 associated with a storeddocument revision history is opened in application 210. As shown in FIG.3B, GUI 300 b may be displayed on display device 110. GUI 300 b includesthe host application window 310 of GUI 300 a that is resized to enable adocument workflow window 320 and a timeline window 330 to be displayedon display device 110 proximate to the host application window 310.Document workflow window 320 may include one or more graphicalrepresentations of events included in the document workflow history ofdocument 215. The graphical representations may be associated with ahierarchy such that the user may browse through the entire documentworkflow history at finer and finer levels of detail. A documentworkflow window 320, according to one embodiment of the presentinvention, is described below in connection with FIG. 6A.

Timeline window 330 may be configured to display a timeline object thatincludes one or more tracks of information related to the eventsgenerated by application 210. Each track of information may include oneor more marker objects corresponding to events that were generated byapplication 210. The timeline object may be configured such that themarker objects are arranged on the timeline object in a chronologicalorder. Timeline window 330 may also include a timeline marker thatidentifies a position in video data 223 that is currently displayed. Asthe timeline marker is moved to a point in the timeline window 330 thatcorresponds to a previous state of document 215, a frame of video data223 that is associated with a position of the timeline marker may beoverlaid on top of host application window 310. Timeline window 330 mayalso include one or more video controls that allow a user to play,rewind, or fast forward video data 223.

As shown in FIG. 3C, video playback window 340 may be displayed directlyover host application window 310. Document workflow applicationextension may cause one or more frames of digital video from video data223 to be displayed in video playback window 340. The digital videoreflects the dynamic state of document 215 over the document workflowhistory of the document 215. The timeline marker in timeline window 330may be positioned at a location in the timeline window 330 thatcorresponds to the frame of digital video currently displayed in videoplayback window 340. A screenshot of timeline window 330, according toone embodiment of the present invention, is described below inconnection with FIG. 10. In alternative embodiments, the application 210may be utilized to change the actual state of document 215 to reflect aprevious point in the document revision history using stored informationabout past events in event data 221.

In one embodiment, document workflow application extension 220 may beconfigured to play back only select portions of the digital video,fast-forwarding through portions that are not particularly interestingto a user. For example, document workflow application extension may beconfigured to play back a first portion of video data 223 in response toa user selecting an event in the document workflow history. Documentworkflow application extension 220 may be configured to only play backthose portions of video data 223 that are associated with data objectsin event data 221 that correspond to events of the same type as theselected event. For example, the selected event may correspond to anoperation where a user drew graphics objects on a digital canvas using apaintbrush tool in application 210. Document workflow applicationextension 220 may be configured to playback each portion of video data223 that is associated with an event related to the paintbrush tool.Document workflow application extension 220 may analyze video data 223and fast-forward through portions of video data 223 that are not relatedto any events related to the paintbrush tool. Consequently, the user mayview a digital video that shows the state of document 215 around eachevent related to the paintbrush tool. In other embodiments, documentworkflow application extension 220 may filter the video data 223 basedon one or more filter criteria selected by a user. In yet otherembodiments, document workflow application extension 220 may filter thevideo data 223 based on one or more search terms entered in a searchquery. For example, a user may search video data 223 for any portions ofthe digital video related to a “paintbrush tool” search query.

FIGS. 4A-4C illustrate the generation of data objects in event data 221based on events generated by application 210, according to one exampleembodiment of the present invention. As shown in FIG. 4A, document 215may be divided into a number of discrete parts such that documentworkflow application extension 220 may associate data objectscorresponding to an event with one or more portions of the document 215.In one embodiment, document 215 is a digital image such as a bitmap witha resolution of 300 dpi (dots per inch). The digital image may bedivided into n×m cells, such as cells 411-430, with each cellrepresenting one or more pixels of the digital image. Although a cellsize of a single pixel may be desired, the optimal cell size for a givensystem may depend on overall processing capacity and memory storagecapabilities. Consequently, each cell may be sized based on one or moresystem characteristics. For example, for the computer system 100 asdescribed in connection with FIG. 1, each cell 411-430 may correspond toa block of pixels that is 4 pixels wide by 4 pixels high (i.e., 16pixels).

Once a user opens or creates a document 215 in application 210, documentworkflow application extension 220 generates a data object correspondingto each event generated by application 210. For example, application 210may be a Paint.Net software application used for editing digital imagedocuments. A user may select a line tool within the Paint.NETapplication environment and draw on a portion of an image. Documentworkflow application extension 220 may receive a message from thePaint.NET application indicating that the user generated a graphicalobject in the image with the line tool. In response to receiving thismessage, the document workflow application extension 220 may check theimage to determine which cells in the image have been modified as aresult of the user generating a graphical object with the line tool. Inone embodiment, document workflow application extension stores the stateof each pixel in the image. When document workflow application extension220 receives a message related to the generation of an event, thedocument workflow application extension 220 compares the pixels of theimage with the stored state of each pixel in the image. If any pixels ina cell are different, then document workflow application 220 associatesthe data object corresponding to the event with that cell of the image.

A user may add a graphic object 410 to document 215. As shown in FIG.4B, the graphic object 410 is associated with cells 416, 417, 418, 420,422, 424, 425, and 426. Application 210 generates an event in responseto the user generating graphic object 410. In response to receiving amessage related to the event, document workflow application extension220 generates a data object in event data 221 corresponding to theevent. The data object in event data 221 may include information aboutthe event, such as an ID of the active layer or particular tool selectedas well as a timestamp that indicates a time corresponding to thegeneration of the event. The types of events that may cause an entry tobe generated in event data 221 may include tool changes, color changes,setting changes, save events, mouse clicks, and document navigations.One of skill in the art will readily appreciate that other types ofevents may also cause a data object to be generated in event data 221and that other types of events are contemplated as being within thescope of the present invention.

As shown in FIG. 4C, event data 221 may include data objects 451, 452,453 and 454 in an array 450 that correspond to one or more eventsrecorded by document workflow application extension 220. For example,event data 221 could include data objects associated with four separateevents 441, 442, 443 and 444 in the document workflow history ofdocument 215. A first event 441 corresponds with a user drawing a circleon a digital canvas of document 215. A second event 442 corresponds withthe user filling the circle with a solid color. A third event 443corresponds with the user drawing a line. A fourth event 444 correspondswith the user editing the length of the line generated in the thirdevent 443.

Document workflow application extension 220 generates data objects inarray 450 corresponding to each of the events 441, 442, 443 and 444.Data object 451 corresponds to the first event 441, data object 452corresponds to the second event 442, data object 453 corresponds to thethird event 443, and data object 454 corresponds to the fourth event444. Each data object 451, 452, 453, and 454 in event data 221 mayinclude information related to the corresponding event such as an ID ofthe tool used to generate a graphical object, an ID of a tool settingthat was changed, a timestamp corresponding to a time associated withthe event, a pointer to a screenshot in image data 222 showing a stateof document 215 at the time of the event, or other data related to theevent. In one embodiment, document workflow application extension 220may generate a timestamp, ID pair to include in the data object thatuniquely identifies the event.

Document workflow application extension 220 may also add pointers to thedata objects to slots in an n×m array 460 that associates the dataobjects 451, 452, 453 and 454 with any cells (411, 412, etc.) indocument 215 that were changed as a result of the corresponding event.As shown, the first event 441 causes changes to cells 416, 417, 418,420, 422, 424, 425, and 426. Consequently, document workflow applicationextension 220 may add a pointer for data object 451 into slots 466, 467,468, 470, 472, 474, 475, and 476 of array 460. Similarly for event 442,document workflow application extension 220 may add a pointer for dataobject 452 into slots 466, 467, 468, 470, 471, 472, 474, 475, and 476 ofarray 460. For event 443, document workflow application extension 220may add a pointer for data object 453 into slots 475 and 479. For event444, document workflow application extension 220 may add a pointer fordata object 454 into slot 479.

Other embodiments extending the functionality of different types ofapplications are contemplated as being within the scope of the presentinvention. The cells (411, 412, etc.) described above are one possiblesolution for an image editing application where the contents of document215 may be efficiently partitioned on a 2D grid of cells. However, otherembodiments may describe “cells” as various parts of a document 215. Forexample in a 3D CAD program, a “cell” may be each of the geometricprimitives stored in the 3D CAD model (i.e., the document 215). Thegeometric primitives may include lines, surfaces, points, etc. Aftereach event is detected by the document workflow application extension220, each of the geometric primitives may be checked to determinewhether the event resulted in a change of any attribute of the geometricprimitive. If an attribute was changed, then document workflowapplication extension 220 may create a new entry in event data 221corresponding to the associated “cell” (i.e., geometric primitive).

In one embodiment, document workflow application extension 220 may beconfigured to capture a screenshot of host application window 310 eachtime an event is generated by application 210. The screenshot may bestored in image data 222 and a pointer to the captured screenshot may beincluded in a corresponding data object in array 450. In otherembodiments, document workflow application extension 220 may crop thecaptured screenshot to display only the cells of document 215 changed bythe corresponding event and store the cropped screenshot in image data222.

In another embodiment, document workflow application extension 220 maybe configured to continuously capture video data 223 that reflects thedocument workflow history of the document 215. Document workflowapplication extension 220 may be configured to capture video at 10 fpsusing any technically feasible technique known in the art. In oneembodiment, document workflow application extension 220 may process thecaptured video data, adding a graphical overlay to indicate the positionof the mouse or to indicate one or more keys that were pressed on thekeyboard, and store the processed video data in video data 223.

FIG. 5 illustrates a graphical user interface displayed in the hostapplication window 310, according to one example embodiment of thepresent invention. As shown in FIG. 5, the host application window 310may display a GUI of application 210. The host application window 310includes a document frame 511 and a drawing toolbar 512. A user may usevarious tools included in the drawing toolbar 512 to create a digitalimage on the canvas in the document frame 511. Although one or moreaspects of the present invention are illustrated using an image editingapplication, it will be appreciated that any other technically feasiblesoftware application capable of generating and editing documents ormedia content may be implemented within application framework 200.

FIGS. 6A-6B illustrate the document workflow window 320, according toone example embodiment of the present invention. As shown, documentworkflow window 320 includes one or more graphical representations 610of events as well as one or more user interface elements 620. Eachgraphical representation 610 represents a portion of the workflowhistory of document 215. In one embodiment, document workflowapplication extension 220 may cause document workflow window 320 to bedisplayed in response to a user command, such as pressing a hotkey orclicking a user interface element in application 210. In order togenerate the one or more graphical representations 610 in documentworkflow window 320, document workflow application extension 220implements a hierarchical clustering algorithm that groups one or moredata objects in event data 221 into one or more clusters of events. Acluster of events may include a subset of data objects from theplurality of data objects corresponding to events generated byapplication 210. For example, a cluster of events may correspond to eachdata object associated with a timestamp between a first time associatedwith a first save event and a second time associated with a second saveevent.

The hierarchical clustering algorithm takes a list of times as input andoutputs a subset of times for use as delimiters to determine the subsetof data objects that is included in the cluster of events. In oneembodiment, document workflow application extension 220 searches throughdata objects (451, 452, etc.) in array 450 to determine whether thereare any data objects related to save events. For each data objectrelated to a save event, document workflow application extension 220adds the timestamp included in the data object to the list of times topass to the next step in the hierarchical clustering algorithm. Documentworkflow application extension 220 then determines if more than athreshold number of data objects are related to save events. Forexample, document 215 may have been saved 10 times and, consequently,there may be 10 corresponding data objects in event data 221. If thereare more than a threshold number of data objects related to save events,then the document workflow application extension 220 sorts thetimestamps in the list of times based on the elapsed time until the nextevent after the save occurred. For example, a timestamp corresponding toa save event for which the document 215 was also closed and then notrevised for another two days would be chosen before a timestampcorresponding to a save event where the user immediately began workingagain. Once the timestamps corresponding to save events are sortedaccording to absolute time until the next recorded event, a thresholdnumber of timestamps are selected. If there are less than or equal to athreshold number of timestamps associated with save events, then thehierarchical clustering algorithm results in every timestamp associatedwith a save event to be selected as a delimiter for generating the oneor more clusters of events. In alternative embodiments, a different typeof event other than a save event may be used to select the subset oftimes for use as delimiters. For example, the hierarchical clusteringalgorithm may select the subset of times based on data objects relatedto adding a layer to document 215, a particular tool of application 210,or when data is imported into the application 210 and other likeheuristics.

In another embodiment, document workflow application extension 220generates the list of times to pass to the next step of the hierarchicalclustering algorithm by adding each timestamp included in a data objectin event data 221 to the list of times. Document workflow applicationextension 220 then sorts the list of input times based on the absolutetime between a time (t) in the input list and the next subsequent time(t_(i+1)) in the input list. For example, time t_(i) would be sortedhigher than time t_(j) if and only if the difference between t_(i+1) andt_(i) is greater than the difference between t_(j+1) and t_(j). Thehierarchical clustering algorithm then selects up to a threshold numberof timestamps from the top of the sorted list, which corresponds to thetimestamps associated with an event corresponding to the largest elapsedtime until the next event generated by application 210.

In yet another embodiment, document workflow application extension 220first attempts to generate the list of times based on each data objectrelated to a save event. If the list of times includes greater than athreshold number of timestamps, then document workflow applicationextension 220 passes the list of times associated with save events tothe next step of the hierarchical clustering algorithm. However, if thelist of times does not include greater than a threshold number oftimestamps, then document workflow application extension 220 willre-generate the list of times by adding each timestamp included in adata object in event data 221, regardless of whether the data object isrelated to a save event, to the list of times. Document workflowapplication extension 220 then passes the list of times to the next stepof the hierarchical clustering algorithm.

The one or more delimiter timestamps that result from processing thelist of times via the hierarchical clustering algorithm may be used bydocument workflow application extension 220 to generate one or moregraphical representations 610 for display in the document workflowwindow 320. Each of the one or more delimiter timestamps marks ademarcation between the events that are represented by one graphicalrepresentation 610 and the events represented by another graphicalrepresentation 610. Document workflow application extension 220 thengenerates a graphical representation 610 associated with all dataobjects in event data 221 that are associated with a timestamp betweentwo delimiter timestamps. For example, if the hierarchical clusteringalgorithm returns two timestamps as delimiter timestamps, the firstdelimiter timestamp having a value of 10 minutes and the seconddelimiter timestamp having a value of 25 minutes, then document workflowapplication extension 220 may generate graphical representations 610corresponding to three clusters of events: (1) a first cluster of eventsthat includes all events from the beginning of the document workflowhistory until the time specified by the first delimiter timestamp; (2) asecond cluster of events that includes all events from the timespecified by the first delimiter timestamp until the time specified bythe second delimiter timestamp; and (3) a third cluster of events thatincludes all events from the time specified by the second delimitertimestamp until the end of the document workflow history.

In one embodiment, each graphical representation 610 includes a firstthumbnail image 611, a second thumbnail image 612, a time indicator 613,a timeline 614, one or more tool icons 615, and additional stateinformation 616 related to document 215. As described above, eachgraphical representation 610 corresponds to a portion of the documentworkflow history (i.e., a subset of data objects stored in event data221 for document 215). Once document workflow application extension 220has determined a cluster of events from which to generate a graphicalrepresentation 610, document workflow application extension 220 maysearch through each of the data objects corresponding to the cluster ofevents to determine the earliest event and the latest event based on thetimes reflected in the timestamps associated with the data objects.

The first thumbnail image 611 may be generated based on a capturedscreenshot in image data 222 corresponding to the earliest event in thecluster of events associated with the graphical representation 610.Similarly, the second thumbnail image 612 may be generated based on acaptured screenshot in image data 222 corresponding to the latest eventin the cluster of events associated with the graphical representation610. In alternative embodiments, the thumbnail images 611, 612 may begenerated by capturing a particular frame of video data 223 at a pointin time in the video associated with the event corresponding to theevent associated with the thumbnail image. In yet other embodiments,clicking on a thumbnail image 611, 612 may interactively change thedisplay of the image in graphical representation 610. For example,clicking on a thumbnail image 611, 612 may toggle between a zoomed inview and a zoomed out view of the document 215 associated with an eventin the cluster of events. In another scenario, clicking on a thumbnailimage 611, 612 may toggle between a front view and a back view of a 3Dmodel. In yet another scenario, clicking on a thumbnail image 611, 612may provide a user with full navigational controls to manually zoom,pan, or rotate a view of document 215.

The time indicator 613 may correspond to the difference between the timereflected by a timestamp in a data object that corresponds to the latestevent and the time reflected by a timestamp in a data object thatcorresponds to the earliest event. Timeline 614 may indicate therelative portion of the document workflow history associated withgraphical representation 610. The marker included in timeline 614 may besized according to the percentage of the document workflow historyassociated with graphical representation 610 and positioned at alocation in timeline 614 relative to when, in the lifetime of document215, the events associated with graphical representation 610 weregenerated. Tool icons 615 may indicate, graphically, one or more toolsin application 210 corresponding to the events associated with graphicalrepresentation 610. In one embodiment, graphical representation 610 maydisplay the most frequently used tools corresponding to the eventsassociated with graphical representation 610. In another embodiment,graphical representation 610 may display a threshold number of tools.Graphical representation 610 may also display addition state information616 related to each of the earliest and latest events. For example, asshown in FIG. 6A, the graphical representations 610 may includeinformation about the number of active layers of document 215 during theearliest event and during the latest event in the cluster of eventsassociated with graphical representation 610. It will be appreciatedthat such state information 616 may be any type of information relatedto the state of document 215 that may be stored in event data 221 orthat such state information 616 may not be included in a graphicalrepresentations 610.

In one embodiment, document workflow window 320 may display up to amaximum threshold number of graphical representations 610 correspondingto different clusters of events in the document workflow history.Document workflow histories and, consequently, the number of dataobjects in event data 221 may grow quite large for complex documents. Itwill be appreciated that the number of events recorded when creating animage in an image editing application may correspond to hundreds orthousands of events. Thus, document workflow window 320 may include userinterface elements for navigation such as expand element 431 andcontract element 432. These navigation user interface elements 431 and432 cause document workflow application extension 220 to generate newgraphical representations 610 for display in document workflow window320.

When a user clicks on the expand element 431 associated with a graphicalrepresentation 610, document workflow application extension 220 willre-run the hierarchical clustering algorithm on the subset of dataobjects associated with the graphical representation 610. Documentworkflow application extension 220 will then generate one or more newgraphical representations 610 for display in document workflow window320 based on one or more new delimiter timestamps selected from thesubset of data objects. Each graphical representation 610 associatedwith two or more events may be expanded using an expand element 631. Inthis manner, a user may navigate down through a hierarchy of graphicalrepresentations 610 until a graphical representation 610 represents asingle event in the document workflow history. Similarly, when a userclicks on the contract element 632, document workflow applicationextension 220 will re-run the hierarchical clustering algorithm on alarger subset of events than is currently associated with each of thegraphical representations 610 displayed in document workflow window 320.Put another way, all of the data objects associated with each of the oneor more graphical representations 610 currently displayed in documentworkflow window 320 will be combined into a single cluster of event forgeneration of one of the one or more new graphical representations to bedisplayed in document workflow window 320.

Document workflow window 320 also includes user interface elements 620.The user interface elements 620 may include a data probe element 621, auser interface probe element 622, a selection probe element 623, arefresh element 624, a close video element 625, and a calendar viewelement 626. A user may use the data probe element 621, the userinterface probe element 622, or the selection probe element 623 toselect a subset of data objects in event data 221 to process via thehierarchical clustering algorithm in order to generate new graphicalrepresentations 610 in document workflow window 320. The functionalityof the data probe 700, the user interface probe 800 and the selectionprobe 900 is described below in connection with FIGS. 7, 8 and 9,respectively.

A user may select the refresh element 624 to cause the graphicalrepresentations 610 in the document workflow window 320 to bere-generated based on any current selections of filter criteria. In oneembodiment, a user may make changes in selections or use filters,discussed below, that effect the subset of data objects associated withthe graphical representations 610 in document workflow window 320.Selecting the refresh element 624 will cause document workflowapplication extension 220 to re-generate the graphical representations610 based on any new criteria or filters selected by a user. The closevideo element 625 may be used to close the video playback window 340 sothat the user may edit document 215 in host application window 310. Thecalendar view element 626 may cause document workflow applicationextension 220 to display the calendar view 1100, described below inconnection with FIG. 11.

As shown in FIG. 6B, the document workflow window 320 may include a tabthat enables a user to select one or more filter criteria to apply tothe data objects in event data 221 for generating graphicalrepresentations 610. Document workflow histories may become quite largefor some documents and, therefore, a user may use filters to manage thetypes of events that are displayed via the graphical representations610. The types of filters may include time filters 650, layer filters652, user filters 653 and tool and workflow filters 654 among other liketypes of filters.

Time filters 651 enable a user to filter the events that are associatedwith the graphical representations 610. In one embodiment, documentworkflow application extension 220 enables a user to specify a certaintimeframe in the document workflow history from which the one or moregraphical representations 610 are generated. For example, by selectingthe “Filter Time” filter in time filters 651, the graphicalrepresentations 610 are generated based on data objects that have atimestamp between any two times specified by a user. In one embodiment,a user may specify times to use in a time filter using two zoom handlesin the timeline window 330, described below. In another embodiment, auser may specify times by entering times into a dialog box or any othertechnically feasible manner. Time filters 651 may also include an “UndoEvents” filter to remove any data objects associated with events thathave been reversed by a subsequent undo action. The time filters 651effect the subset of data objects processed by the hierarchicalclustering algorithm and, consequently, the generation of graphicalrepresentations 610. However, in one embodiment, the time filters 651 donot affect the playback of video data 223 in video playback window 340and any filtered events that are not associated with the graphicalrepresentations 610 in the document workflow window 320 may still beviewed by a user in the video playback window 340.

Layer filters 652 are filters that may be implemented with image editingapplications or any other types of applications that include multiplelayers. Layers enable a user to create graphic objects on a hierarchy oftransparent canvases that merge to form a single digital image. Pixelsincluded in a top layer are fully visible in the resulting digitalimage, pixels included in the second layer are visible if not occludedby the pixels in the top layer, pixels included in the third layer arevisible if not occluded by the pixels in the top layer or pixelsincluded in the second layer, etc. Layers may be used to create masksfor performing operations on pixel data included on other layers in theimage. Layers may be deleted, reordered, made partially transparent, ormerged with one or more other layers. Layer filters 652 enable a user toselect events associated with specific layers of the digital image inorder to generate the one or more graphical representations 610.

A “Deleted Layers” filter in layer filters 652 enables a user to filterout events that are associated with any deleted layers. Consequently,the graphical representations 610 exclude any data objects in event data221 that are associated with layers that have been deleted in document215. An “Invisible Layers” filter in layer filters 652 may filter outdata objects that are not visible because either the user has set alayer to be hidden or the user has set the transparency of a layer tofully transparent. An “Occluded Layers” filter in layer filters 652 mayfilter out data objects that are associated with any layers that arefully occluded by other layers. If a user selects this filter, documentworkflow application extension 220 may determine whether any pixels onan associated layer are visible in the resulting digital image. If nopixels are visible, then that layer is considered fully occluded and anydata objects associated with that layer are not included in the subsetof data objects processed by the hierarchical clustering algorithm togenerate the graphical representations 610. In one embodiment, a usermay be able to select a specific layer using one or more user interfaceelements within application 210. Document workflow application extension220 may then be configured to filter data objects associated with theselected layer in order to generate graphical representations 610 thatreflect the events associated with that layer.

User filters 653 are filters that enable a user to generate graphicalrepresentations 610 that reflect data objects generated by one or moreusers of application 210. As shown, document workflow window 320 mayenable a user to select one or more users (if document 215 is associatedwith more than one user) with which to filter the subset of data objectsin event data 221 that are processed by the hierarchical clusteringalgorithm to generate graphical representations 610.

Tool and workflow filters 654 are filters that are associated with afeature of application 210. Such features may includes tools, layers, orapplied effects as well as other features included in application 210that may be associated with a data object in event data 221. In oneembodiment, document workflow window 320 enables a user to select asingle feature (e.g., a line tool), an entire category (e.g., drawingtools), or a set of features across multiple categories (e.g., alldrawing tools and applied effects, such as a Gaussian blur effect). Inanother embodiment, document workflow application extension 220 mayinclude preset groups of features or allow users to create preset groupsof features such as a “Creations” group that selects all features thatmay add content to document 215 or a “Features not Used Before” groupthat selects all features that the current user has not used before. Inyet another embodiment, document workflow application extension mayenable a user to select one or more features in the tool and workflowfilters 654.

In one embodiment, all of the filters described above may be used incombination with any of the probing tools, described below. Once a userselects which filters to apply, the user may use a probing tool, such asdata probe 710 or the user interface probe 810, to generate one or moregraphical representations 610 in document workflow window 320.

FIGS. 7A-7B illustrate the data probe 710, according to one exampleembodiment of the present invention. As shown in FIG. 7A, the data probe710 may be used to specify a region within document 215 for generationof one or more graphical representations 610 displayed in documentworkflow window 320. In one embodiment, the size of the data probe 710may be adjusted using a scroll wheel of a mouse device 109 or otherinput means. Similarly, the position of the data probe 710 may becontrolled by the position of the mouse cursor. In response to receivinga selection by the data probe 710, such as in response to a mouse click,document workflow application extension 220 may generate one or more newgraphical representations 610 based on a subset of data objects in eventdata 221 that are associated with the one or more cells of document 215that overlap with the data probe 710. For example, when a user clicksthe mouse 109, the current aperture (i.e., the square that is overlaidon the host application window 310) of the data probe 710 is compared toeach of the cells of document 215. For each cell 411-430 that overlapswith the aperture of the data probe 710, document workflow applicationextension 220 may access the corresponding slot 461-680 in array 460 todetermine which data objects in event data 221 are associated with theregions of document 215 that overlap with the data probe 710. Thedocument workflow application extension 220 may then generate a list oftimestamps corresponding to each data object associated with theoverlapping cells and that also pass any currently selected filtercriteria to pass to the hierarchical clustering algorithm to generatetime delimiters for use in generating one or more graphicalrepresentations 610 that correspond to only that portion of document 215that is associated with the aperture of the data probe 710.

In another embodiment, data probe 710 may be used as a lens into thedocument's workflow history. Document workflow application extension 220may access the plurality of data objects in event data 221 and determinea subset of data objects that are associated with regions of document215 that overlap with the aperture of the data probe 710. A user maythen navigate through the document workflow history by going forward orbackward through the events corresponding to the subset of data objects.The aperture of the data probe 710 may display cropped versions of thecaptured screenshots in image data 222 associated with each data objectin the subset of data objects. Thus, inside the aperture of data probe710, the user may visualize a previous state of document 215 at a pointin time corresponding to one of the events associated with the subset ofdata objects. Simultaneously, outside the aperture of data probe 710,the user may still visualize a current state of document 215, which mayprovide context to the final result generated by the workflow history.As shown in FIG. 7B, document 215 includes a star drawn using a linetool. The data probe 710 may be used to visualize document 215 at aprevious state corresponding to one of the data objects in the subset ofdata objects. Outside of the aperture of data probe 710, the currentstate of document 215 remains visible. Moving the aperture of the dataprobe 710 around the document frame 511 will reveal the state ofdocument 215 corresponding to one of the data objects in a subset ofdata objects generated based on the location of the data probe 710.

FIG. 8 illustrates the user interface probe 810, according to oneexample embodiment of the present invention. As shown in FIG. 8, theuser interface probe 810 is similar to the data probe 710 describedabove except that the aperture of the user interface probe 810 is usedto generate graphical representations 610 based on data objects in eventdata 221 that are associated with one or more user interface elements ofthe host application window 310. In one embodiment, the user interfaceprobe 810 may be a different color than the data probe 710 todistinguish between the two tools. The size and position of the apertureof the user interface probe 810 may be adjusted in a similar manner asthe data probe 710, described above.

The user interface probe 810 may be used to select a subset of dataobjects that are associated with tool icons, floating palettes, settingicons, menu items, and dialog boxes in the host application window 310.In response to a selection with the user interface probe 810, documentworkflow application extension 220 may generate one or more graphicalrepresentations 610 in document workflow window 320 based on a subset ofdata objects in event data 221 that are associated with any of the userinterface elements in host application window 310 that overlap with thecurrent aperture of the user interface probe 810. In another embodiment,selecting a menu item of host application window 310 while holding ahotkey, such as F2, is equivalent to selecting the menu item with theuser interface probe 810.

For example, as shown in FIG. 8, the aperture of the user interfaceprobe 810 overlaps with both a text tool and a rectangle tool in toolbar512 of the host application window 310. In response to such a selectionwith the user interface probe 810, document workflow applicationextension 220 traverses through each of the data objects in event data221 and determines whether the data object is associated with an eventrelated to either the text tool or the rectangle tool. If the dataobject is associated with a related event, then document workflowapplication extension 220 adds the timestamp included in that dataobject to a list of times to pass to the hierarchical clusteringalgorithm. If the data object is not associated with a related event,then document workflow application extension 220 moves to the next dataobject. Document workflow application extension 220 then generates oneor more graphical representations 610 in document workflow window 320based on a subset of events corresponding to times returned from thehierarchical clustering algorithm.

FIG. 9 illustrates the selection probe 910, according to one exampleembodiment of the present invention. As shown in FIG. 9, a user maycreate a selection marquee based on native selection tools included inapplication 210. For example, the user may use a rectangle selectiontool or a freeform selection tool of application 210. When a userselects the selection probe element 623 in document workflow window 320,document workflow application extension 220 will generate new graphicalrepresentations 610 based on the current selection in document 215. Inthere is no current selection when a user selects the selection probeelement 623, then the user may user a native selection tool inapplication 210 to select a portion of document 215. Once the selectionis made, document workflow application extension 220 may generate thenew graphical representations 610 in a similar manner to that describein connection with data probe 710 for any cells of document 215 thatoverlap with the current selection area.

FIG. 10 illustrates a timeline window 330, according to one exampleembodiment of the present invention. The timeline window 330 may be usedto control playback of one or more frames of digital video in video data223 in video playback window 340. When a user switches focus to thetimeline window 330, document workflow application extension 220 maycause video playback window 340 to be overlaid over host applicationwindow 310. Video data 223 associated with document 215 may then beplayed in the video playback window 340 to display the workflow historyof document 215. Such playback of video data 223 associated withdocument 215 enables a user to visualize previous operations or changesassociated with the creation of document 215. A timeline marker 1010indicates the current position of the video in the video playback window340 and may be dragged to scrub the video forward or backward in videoplayback window 340. In one embodiment, timeline window 330 may alsoinclude playback controls 1023 such as play, pause, stop, rewind, andfast forward that will cause video playback to begin at a frame of videodata 223 that corresponds to the current position of the timeline marker1010.

As shown in FIG. 10, timeline window 330 may include timing information1020, an event track 1030, a tools track 1040, a users track 1050, anannotation track 1060, and one or more other tracks (such as a colorstrack or layers track in an image editing application) related toapplication 210. The timing track 1020 includes video timing informationthat may be in an absolute time, such as a date and time of a systemclock associated with a particular frame of video data 223, or anelapsed time, such as a relative time in tenths of seconds that document215 was open in application 210. The timing track 1020 may include oneor more markers 1021 that correspond to a timeframe in the video data223 associated with a graphical representation 610 currently displayedin the document workflow window 320.

A user may zoom in or out of the timeline window 330 to display only aportion of the total timeline associated with the document workflowhistory. In one embodiment, the timeline track 1020 includes zoomhandles 1022 that allow a user to zoom into a portion of the timeline.As shown, each of the tracks in the timeline window 330 (i.e., theevents track 1030, the tools track 1040, etc.) will be repopulated toonly show the associated marker objects that correspond to a data objectin event data 221 with a timestamp that reflects a time in between thetwo zoom handles 1022. In another embodiment, when a user clicks on agraphical representation 610 in the document workflow window 320, thetimeline may be automatically zoomed into that portion of the timelinewindow 330 corresponding to the subset of data objects associated withthe graphical representation 610.

The event track 1030 includes one or more marker objects 1031 that eachcorrespond to a different data object in event data 221. Each markerobject 1031 is located at a position in the event track 1030 thatcorresponds to the timestamp included in the associated data object inevent data 221. In one embodiment, a marker object 1031 may be an iconrelated to the particular event type associated with that marker object1031. In another embodiment, the icon may be of variable width toprevent overlap of multiple marker objects on the event track 1030. Inyet another embodiment, the icon may have a variable width thatcorresponds to the duration of time represented by the marker object1031. For example, if a dialog box was open for 35 seconds, then theassociated marker object 1031 would have a width representing 35 secondsof time on the timeline.

The event track 1030 may be expanded to include one or more subtracksthat display information about the particular event associated with amarker object 1031 in the event track 1030. For example, as shown inFIG. 10, the subtracks may include information about settings, dialogboxes, user actions, or tools selected in application 210 that arerelated to the marker object 1031. Additional marker objects 1032 s maybe placed on the subtracks to indicate that the event associated withmarker object 1031 includes information related to one of the subtrackcategories.

In one embodiment, placing a mouse cursor over a marker object 1031 inthe events track 1030 or one of the additional marker objects 1032 inthe subtrack may cause document workflow application extension 220 todisplay a tooltip that provides a user with additional information aboutthat particular event. For example, hovering the mouse cursor over amarker object 1032 on the settings subtrack may display informationabout the particular setting that was changed and the value that thesetting was changed to. Tooltips may be displayed for an action marker,a tool marker, a setting marker, a save point, a user marker, or a colormarker among other types of marker objects 1031. In one embodiment,hovering the mouse cursor over a marker object 1032 on the dialogsubtrack may display the actual dialog box in application 210 that isassociated with the marker object 1032 and any changes to the dialog boxmay be highlighted by using a phosphor or other special effect to drawthe user's focus to the particular setting in the dialog box that wasadjusted by the event. In another embodiment, a user may be able tocycle through a plurality of images of the dialog box, where each imagerepresents a different state of the dialog box, from when the dialog boxwas first opened to when the dialog box was closed. A key on thekeyboard 108 or a button or wheel on the mouse 109 may be used to cyclethrough the plurality of images.

In yet another embodiment, marker objects 1031 may be associated withother related marker objects 1031 on one or more tracks in timelinewindow 330. When a user hovers the mouse cursor over a tool marker, oneor more associated marker objects 1031 may be highlighted to show thatthere is an association between the two marker objects 1031. Forexample, a marker object 1032 on the tools subtrack may be associatedwith a separate marker object 1032 on the settings subtrack. The markerobject 1032 on the settings subtrack may correspond to a change in avalue of a setting associated with the tool that corresponds to themarker object 1032 on the tools subtrack.

The tools track 1040 (unlike the tools subtrack associated with theevent tack 1030) may indicate which tool of application 210 was selectedat any point in time in the document workflow history. The tools track1040 indicates an application state rather than an explicit event in thedocument workflow history (i.e., a marker object in the tool track 1040indicates that a tool in application 210 was active during a period oftime, but not necessarily that the tool was used). The user track 1050indicates a user that was editing document 215 at a given point in thedocument workflow history. For documents with a single author, there mayonly be one marker on the user track 1050. However, many documents mayhave multiple contributors, and the user track 1050 may displayinformation on the various authors that have opened document 215. Inaddition, the user track 1050 may include save markers 1051 thatindicate a save event where the user saved document 215. In oneembodiment, a user may right-click on a save marker 1051 and restore aprevious version of the document 215 associated with the save eventcorresponding to the save marker 1051. The annotation track 1060 mayinclude one or more marker objects that correspond to any annotationswhich have been added to video data 223. Annotation markers may beconfigured to identify the user that added the annotation to video data223 as well as the text or graphic that was added by the annotationevent.

As also shown in FIG. 10, one or more other tracks may be included intimeline window 330. For example, the colors track may display theselected color or selected colors at a given point in the documentrevision history. The layers track may display the active layers ofdocument 215. The activity track may display the relative amount ofactivity, such as by measuring the number or frequency of mouse clicks,at a given point in time in the document workflow history.

In one embodiment, a user may be able to select a portion of thedocument revision history in the timeline window 330, such as bydragging the timeline marker 1010 or dragging the zoom handles 1022, inorder to select a subset of events within the document revision history.Then, the user may right-click on the timeline window 330 in theselected portion of the timeline to apply the selected portion of thedocument revision history to a new document 215. In alternativeembodiments, a user may interact with other features of the timelinewindow 330 such as by right-clicking a marker object 1031, 1032, etc.and applying the operation corresponding to the marker object to thecurrent document 215. In yet other embodiments, users may be able todrag-and-drop a marker object 1031, 1032, etc. from the timeline window330 onto a document 215 to apply the corresponding operation to thedocument 215. For example, a user could drag-and-drop a marker object1032 associated with a gradient tool from the tools subtrack in thetimeline window 330 to apply the associated gradient operation to adocument 215. Such features may be applied to the document 215associated with the currently open document revision history or may beapplied to other documents or even applications (e.g., a gradient toolin Paint.net could be applied to a document opened in a Photoshopapplication). In another embodiment, a portion of a document revisionhistory may be selected in the timeline window 330 and export to sharewith other users such as through an email attachment or instant message.

FIG. 11 illustrates a graphical user interface for a calendar view 1100of the document workflow history, according to one example embodiment ofthe present invention. A user may select the calendar view element 626in the document workflow window 320 to cause document workflowapplication extension 220 to display the calendar view 1100 of thedocument workflow history. The calendar view 1100 enables a user to seethe state of a document 215 as it existed on different dates. In oneembodiment, the calendar view 1100 may display a calendar for the monthassociated with the current date. The calendar view 1100 may alsoinclude navigation controls 1111 and 1112 to navigate to differentmonths. In other embodiments, the calendar view 1100 may display datesby week, bi-weekly, bi-monthly, or annually in a single view.

An icon associated with the state of document 215 on a given date may bedisplayed on a date of the calendar view 1100. As shown, a first icon1121, that represents a first state of document 215 as saved on Mar. 3,2010, is displayed in the calendar view 1100. A second icon 1122, thatrepresents a second state of document 215 on Mar. 11, 2010, is alsodisplayed in the calendar view 1100. In one embodiment, hovering themouse cursor over an icon in the calendar view 1100 may cause a tooltipto display information related to the user or users that accesseddocument 215 on that date. In another embodiment, clicking on an icon inthe calendar view 1100 may cause the timeline window 330 to zoom in on atimeframe corresponding to that particular date. In yet anotherembodiment, clicking on an icon in the calendar view 1100 may causevideo playback window 340 to be displayed and video data 223 associatedwith that particular date to be played in the video playback window 340.

FIGS. 12A-12B illustrate adding annotations 1210 to one or more framesof video data 223, according to one example embodiment of the presentinvention. Again, document workflow application extension 220 may beconfigured to record and play back video data 223 in the video playbackwindow 340. The captured video data 223 enables a user to visualize theprevious actions and events that culminated in document 215. The richcontent that is captured by the document workflow application extension220 may be utilized as a teaching tool to inform other users how aparticular effect or element of document 215 was created. As shown inFIG. 12A, a user may navigate to a particular frame of the video usingthe timeline marker 1010 in timeline window 330 or the video playbackcontrols 1023. In one embodiment, a user may add an annotation to aframe of video data 223 by pressing a hotkey such as F8 to insert astring of text or graphic that is overlaid on top of the frame of videoin video playback window 340. In another embodiment, a user may be ableto add audio annotations to a frame or frames of video.

In addition to annotating frames of video data 223, a user may annotatea portion of the document revision history using the timeline window 330by selecting a portion of the timeline window using the zoom handles1022 or dragging the timeline marker 1010 with a mouse. For example, theuser could select a portion of the timeline and indicate that theselected portion is an area of interest or, alternatively, an area oflittle interest. A user may also be able to mark a portion of thedocument revision history as private, thereby disabling other users frombeing able to view information related to that portion of the documentrevision history. Such hidden areas of the document revision history maybe indicated on the timeline window 330 with annotated comments thatindicate that portion of the document revision history has been madeprivate by the author of the document 215.

As shown in FIG. 12B, document workflow application extension 220 mayadd a graphical overlay to the frame of digital video in video data 223that includes a string of text entered by a user. The annotation 1210may help a user understand how an effect was created in document 215.Document workflow application extension 220 may store the annotationtext as metadata along with frame of video data 223 and generate thegraphical overlay at runtime. In addition, document workflow applicationextension 220 may also generate a graphical overlay to indicatekeystrokes 1220 or any actions or position data 1230 associated with themouse device 109. In other embodiments, document workflow applicationextension 220 may modify the pixel data in one or more frames of videodata 223 such that the annotation is permanently included in the digitalvideo.

FIG. 13 is a flowchart of method steps 1300 for capturing a workflowhistory of an electronic document 215, according to one exampleembodiment of the present invention. Although the method steps aredescribed in conjunction with the systems of FIGS. 1-12, persons skilledin the art will understand that any system configured to perform themethod steps, in any order, is within the scope of the inventions.

The method 1300 begins at step 1310, where document workflow applicationextension 220 receives an event generated by application 210. The eventmay be generated by application 210 in response to a user command andmay result in a modification to document 215. At step 1312, documentworkflow application extension 220 generates a data object in event data221 that stores information related to the event. In one embodiment, thedata object may include a timestamp and an ID that identifies a featureof application 210. At step 1314, document workflow applicationextension 220 captures a screenshot (i.e., a digital image) of document215 that reflects a state of document 215 at a time corresponding to thegeneration of the event. At step 1316, document workflow applicationextension 220 associates the data object generated in step 1312 with aportion of document 215 modified by the event as well as the screenshotcaptured at step 1314. In one embodiment, document 215 is a digitalimage that is divided into one or more cells that include a block ofpixels. Document workflow application extension 220 associates the dataobject with each cell of pixels in document 215 that was modified as aresult of the event. In one embodiment, document workflow applicationextension 220 also stores a pointer to the captured screenshot in thedata object. At step 1318, document workflow application extension 220captures a plurality of frames of digital video that reflects a state ofdocument 215 at a time corresponding to the generation of the event. Inone embodiment, document workflow application extension 220 capturesdigital video of host application window 310 at 10 frames per second andstores the digital video in video data 223. At step 1320, documentworkflow application extension 220 associates the data object with atleast one frame of the digital video. In one embodiment, documentworkflow application extension 220 stores a pointer to a first frame ofdigital video in the data object. At step 1322, document workflowapplication extension 220 stores the data object, the digital image, andthe digital video in system memory 104 or in non-volatile storage suchas system disk 114. The data object, the digital image, and the digitalvideo may be associated with document 215 such that document workflowapplication extension 220 may retrieve the data object, the digitalimage, and the digital video when a user opens document 215 inapplication 210.

FIG. 14 is a flowchart of method steps 1400 for generating andnavigating a graphical representation of a workflow history of anelectronic document, according to one example embodiment of the presentinvention. Although the method steps are described in conjunction withthe systems of FIGS. 1-12, persons skilled in the art will understandthat any system configured to perform the method steps, in any order, iswithin the scope of the inventions.

The method 1400 begins at step 1410, where document workflow applicationextension 220 accesses a plurality of data objects in event data 221. Inone embodiment, each data object in event data 221 stores informationrelated to an event generated by application 210. At step 1412, documentworkflow application extension 220 identifies a first time and a secondtime via a hierarchical clustering algorithm. In one embodiment,document workflow application extension 220 analyzes the plurality ofdata objects via a hierarchical clustering algorithm. The first time andthe second time may be identified based on at least one data objectrelated to a save event. In another embodiment, the first time and thesecond time may be identified based on the largest elapsed time betweensubsequent events. At step 1414, document workflow application extension220 selects a set of data objects from the plurality of data objects inevent data 221 based on the first time and the second time. In oneembodiment, each data object in the set of data objects includes atimestamp that reflects a time that is either equal to the first time,equal to the second time, or falls between the first time and the secondtime.

At step 1416, document workflow application extension 220 generates agraphical representation that represents the set of data objects. In oneembodiment the graphical representation includes a first thumbnail imagethat reflects a state of document 215 prior to any of the eventscorresponding to a data object in the set of data objects and a secondthumbnail image that reflects a state of document 215 after all of theevents corresponding to a data object in the set of data objects. Thegraphical representation may also include a duration indicator thatreflects a difference between the times reflected in the timestampsstored in the first data object and the last data object in the set ofdata objects. At step 1418, document workflow application extension 220causes the graphical representation to be displayed in a graphical userinterface associated with the document workflow application extension220. In one embodiment, the graphical representation is displayed in thedocument workflow window 320 proximate to the host application window310.

At step 1420, document workflow application extension 220 determineswhether a user selects a navigation element associated with thegraphical representation 610 in document workflow window 320. If a userhas not selected the navigation element, then document workflowapplication extension 220 waits until the navigation element isselected. If a user selects the navigation element, then method 1400proceeds to step 1422, where document workflow application extension 220generates a new graphical representation 610 that represents subset ofdata objects based on the set of data objects associated with thegraphical representation 610. For example, document workflow applicationextension 220 may generate a new graphical representation 610 inresponse to a user expanding one of the graphical representations indocument workflow window 320. Document workflow application extension220 may generate a new subset of data objects based on a portion of theset of data objects represented by the graphical representation 610. Inthis manner, a user may visualize a smaller subset of events within thedocument workflow history. At step 1424, document workflow applicationextension 220 causes the new graphical representation 610 to bedisplayed in the document workflow window 320.

FIG. 15 is a flowchart of method steps 1500 for generating anddisplaying video data representing a workflow history of an electronicdocument, according to one example embodiment of the present invention.Although the method steps are described in conjunction with the systemsof FIGS. 1-12, persons skilled in the art will understand that anysystem configured to perform the method steps, in any order, is withinthe scope of the inventions.

The method 1500 begins at step 1510, where document workflow applicationextension 220 captures a plurality of frames of video data 223. In oneembodiment, document workflow application extension 220 captures aplurality of frames of digital video at 10 fps, where each framecorresponds to a screenshot of host application window 310. At step1512, document workflow application extension 220 accesses a pluralityof data objects in event data 221. In one embodiment, each data objectin event data 221 stores information related to an event generated byapplication 210. At step 1514, document workflow application extension220 associates each data object in the plurality of data objects with atleast one frame of digital video in video data 223. At step 1516,document workflow application extension 220 receives a selection of anevent corresponding to a first event type. In one embodiment, eventtypes may include settings events, tool events, user events, saveevents, or any other type of event that is related to application 210.

At step 1518, document workflow application extension 220 causes a firstportion of video data 223 to be displayed in video playback window 340.At least one frame of the first portion of video data 223 is associatedwith a data object corresponding to an event of the first event type. Atstep 1520, document workflow application extension 220 skips a secondportion of video data 223. In one embodiment, document workflowapplication extension 220 is configured to fast forward to a thirdportion of video data 223. At step 1522, document workflow applicationextension 220 causes the third portion of video data 223 to be displayedin video playback window 340. At least one frame of the third portion ofvideo data 223 is associated with a data object corresponding to anevent of the first event type.

FIG. 16 is a flowchart of method steps 1600 for configuring anapplication based on a workflow history of an electronic document,according to one example embodiment of the present invention. Althoughthe method steps are described in conjunction with the systems of FIGS.1-12, persons skilled in the art will understand that any systemconfigured to perform the method steps, in any order, is within thescope of the inventions.

The method 1600 begins at step 1610, where document workflow applicationextension 220 accesses a plurality of data objects in event data 221. Inone embodiment, each data object in event data 221 stores informationrelated to an event generated by application 210. At step 1612, documentworkflow application extension 220 generates a timeline object thatincludes one or more tracks of information related to the workflowhistory of document 215. In one embodiment, the timeline object includestiming information 1020, an event track 1030, a tools track 1040, ausers track 1050, an annotation track 1060, and one or more other tracksrelated to data associated with application 210. Each information trackof timeline window 330 may include one or more marker objects associatedwith a data object in event data 221. At step 1614, document workflowapplication extension 220 causes the timeline window 330 to be displayedin a timeline window 330 proximate to a host application window 310.

At step 1616, document workflow application extension 220 receives aselection of a first marker object in the timeline object. The firstmarker object is associated with at least one data object in event data221. At step 1618, document workflow application extension 220configures application 210 based on the information in the data objectassociated with the first marker object. In one embodiment, a user mayright-click on a marker object in timeline window 330 to configure afeature of application 210 or to perform a scripted action based on theinformation in the data object associated with the marker object. Forexample, a marker object may be associated with a data objectcorresponding to an event generated when a user selected a line tool inapplication 210. By right-clicking on the marker object, the line toolwill be selected in application 210 such that the user may generate aline in document 215.

FIG. 17 is a flowchart of method steps 1700 for displaying a workflowhistory of a document, according to one example embodiment of thepresent invention. Although the method steps are described inconjunction with the systems of FIGS. 1-12, persons skilled in the artwill understand that any system configured to perform the method steps,in any order, is within the scope of the inventions.

The method 1700 begins at step 1710, where document workflow applicationextension 220 accesses a plurality of data objects in event data 221. Inone embodiment, each data object in event data 221 stores informationrelated to an event generated by application 210. At step 1712, documentworkflow application extension 220 filters the plurality of data objectsin event data 221 to create a subset of filtered data objects. Documentworkflow application extension 220 filters the data objects in eventdata 221 based on one or more filter criteria. In one embodiment, thefilter criteria may be selected by a user via one or more user interfaceelements included in document workflow window 320. In anotherembodiment, the filter criteria may be selected using native toolsincluded in application 210. In yet another embodiment, documentworkflow application extension 220 selects the filter criteria based onan algorithm such as by filtering out every data object related to afeature of application 210 that the current user has never selected.

At step 1714, document workflow application extension 220 identifies afirst time and a second time via a hierarchical clustering algorithm. Inone embodiment, document workflow application extension 220 analyzes theset of filtered data objects via a hierarchical clustering algorithm.The first time and the second time may be identified based on at leastone data object related to a save event. In another embodiment, thefirst time and the second time may be identified based on the largestelapsed time between subsequent events. At step 1716, document workflowapplication extension 220 selects a subset of filtered data objects fromthe set of filtered data objects in event data 221 based on the firsttime and the second time. In one embodiment, each data object in thesubset of filtered data objects includes a timestamp that reflects atime that is either equal to the first time, equal to the second time,or falls between the first time and the second time.

At step 1718, document workflow application extension 220 generates agraphical representation that represents the subset of filtered dataobjects. In one embodiment the graphical representation includes a firstthumbnail image that reflects a state of document 215 prior to any ofthe events corresponding to a data object in the subset of filtered dataobjects and a second thumbnail image that reflects a state of document215 after all of the events corresponding to a data object in the subsetof filtered data objects. At step 1720, document workflow applicationextension 220 causes the graphical representation to be displayed in agraphical user interface associated with the document workflowapplication extension 220.

In sum, the present application describes a system and technique fordisplaying a revision history of a document. The disclosed systemincludes a graphical user interface for displaying graphicalrepresentations of events generated by an application. Each of theevents generated by the application is stored in a data structure thatis associated with one or more portions of the document. The datastructure may also be associated with a digital image that reflects thestate of the document at the time the event was generated and one ormore frames of digital video captured substantially simultaneously withthe generation of the event. The system then displays the revisionhistory via graphical representations in the graphical user interface.Each graphical representation represents a portion of the revisionhistory of the document. A user may navigate through various graphicalrepresentations of events that are generated using a hierarchicalclustering algorithm. A user may also view digital video of those eventsthat are played back in a window overlaid over the host applicationwindow.

One advantage of the disclosed approach is that the system provides aflexible and intuitive approach for displaying and navigating therevision history of a document. Even a large revision history thatincludes hundreds of user operations may be reduced to a simplegraphical representation that may be navigated by a user to visualizethe revision history at finer and finer detail. A user may use toolswithin the system to filter or search the revision history forparticular types of user operations. The hierarchical, high-levelclustering algorithm also presents each of the user operations withinthe context of the complete revision history, allowing a user tovisualize and learn various techniques for creating or modifying thecontent of a document.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the present invention may be devisedwithout departing from the basic scope thereof. For example, aspects ofthe present invention may be implemented in hardware or software or in acombination of hardware and software. One embodiment of the presentinvention may be implemented as a program product for use with acomputer system. The program(s) of the program product define functionsof the embodiments (including the methods described herein) and can becontained on a variety of computer-readable storage media. Illustrativecomputer-readable storage media include, but are not limited to: (i)non-writable storage media (e.g., read-only memory devices within acomputer such as CD-ROM disks readable by a CD-ROM drive, flash memory,ROM chips or any type of solid-state non-volatile semiconductor memory)on which information is permanently stored; and (ii) writable storagemedia (e.g., floppy disks within a diskette drive or hard-disk drive orany type of solid-state random-access semiconductor memory) on whichalterable information is stored. Such computer-readable storage media,when carrying computer-readable instructions that direct the functionsof the present invention, are embodiments of the present invention.

In view of the foregoing, the scope of the present invention isdetermined by the claims that follow.

1. A method for generating and navigating a graphical representation ofa workflow history of an electronic document, the method comprising:accessing a plurality of data objects stored in a memory, wherein eachdata object stores information related to a different event generated byan application that is configured to modify the document; identifying afirst time and a second time during which the application generatesevents; selecting a set of data objects from the plurality of dataobjects, wherein each data object in the set of data objects includes atimestamp reflecting a time that is equal to either the first time orequal to the second time or falls in between the first time and thesecond time; generating a graphical representation of the set of dataobjects; and causing the graphical representation to be displayed in agraphical user interface associated with the application.
 2. The methodof claim 1, wherein the step of identifying comprises: determiningwhether at least one data object in the plurality of data objects isrelated to a save event; and if at least one data object is related to asave event, then identifying the first time and the second time based onone or more timestamps included in data objects related to save eventsin the plurality of data objects, or if no data object is related to asave event, then identifying the first time and the second time based onone or more timestamps included in data objects related to other typesof events in the plurality of data objects.
 3. The method of claim 1,wherein the step of identifying comprises: for each data object in theplurality of data objects, calculating an elapsed time between the eventassociated with each data object and the next subsequent event generatedby the application; and identifying the first time and the second timebased on one or more timestamps included in the plurality of dataobjects, wherein the one or more timestamps are selected based on theelapsed times calculated for each data object in the plurality of dataobjects.
 4. The method of claim 3, wherein the one or more timestampsare selected from the data objects corresponding to the longest elapsedtimes.
 5. The method of claim 1, further comprising: generating acalendar view of the workflow history of the document, wherein one ormore thumbnail images that reflect a state of the document on aparticular day are included in the calendar view; and causing thecalendar view to be displayed in the graphical user interface associatedwith the application.
 6. The method of claim 1, wherein the graphicalrepresentation includes a first thumbnail image that reflects a state ofthe document prior to the occurrence of the events associated with theset of data objects, a second thumbnail image that reflects a state ofthe document after the occurrence of the events associated with the setof data objects, a duration indicator that identifies a differencebetween the timestamp associated with a first event in the set of eventsand the timestamps associated with a last event in the set of events,and a timeline marker that identifies the percentage of the workflowhistory of the document that corresponds to the set of data objects. 7.The method of claim 1, further comprising: in response to a userselecting an element included in the graphical representation,generating a new graphical representation of a subset of data objectsbased on the set of data objects; and causing the new graphicalrepresentation to be displayed in the graphical user interfaceassociated with the application.
 8. A computer-readable storage mediumcontaining a program which, when executed, performs an operation forgenerating and navigating a graphical representation of a workflowhistory of an electronic document, the operation comprising: accessing aplurality of data objects stored in a memory, wherein each data objectstores information related to a different event generated by anapplication that is configured to modify the document; identifying afirst time and a second time during which the application generatesevents; selecting a set of data objects from the plurality of dataobjects, wherein each data object in the set of data objects includes atimestamp reflecting a time that is equal to either the first time orequal to the second time or falls in between the first time and thesecond time; generating a graphical representation of the set of dataobjects; and causing the graphical representation to be displayed in agraphical user interface associated with the application.
 9. Thecomputer-readable storage medium of claim 8, wherein the step ofidentifying comprises: determining whether at least one data object inthe plurality of data objects is related to a save event; and if atleast one data object is related to a save event, then identifying thefirst time and the second time based on one or more timestamps includedin data objects related to save events in the plurality of data objects,or if no data object is related to a save event, then identifying thefirst time and the second time based on one or more timestamps includedin data objects related to other types of events in the plurality ofdata objects.
 10. The computer-readable storage medium of claim 8,wherein the step of identifying comprises: for each data object in theplurality of data objects, calculating an elapsed time between the eventassociated with each data object and the next subsequent event generatedby the application; and identifying the first time and the second timebased on one or more timestamps included in the plurality of dataobjects, wherein the one or more timestamps are selected based on theelapsed times calculated for each data object in the plurality of dataobjects.
 11. The computer-readable storage medium of claim 10, whereinthe one or more timestamps are selected from the data objectscorresponding to the longest elapsed times.
 12. The computer-readablestorage medium of claim 8, the operation further comprising: generatinga calendar view of the workflow history of the document, wherein one ormore thumbnail images that reflect a state of the document on aparticular day are included in the calendar view; and causing thecalendar view to be displayed in the graphical user interface associatedwith the application.
 13. The computer-readable storage medium of claim8, wherein the graphical representation includes a first thumbnail imagethat reflects a state of the document prior to the occurrence of theevents associated with the set of data objects, a second thumbnail imagethat reflects a state of the document after the occurrence of the eventsassociated with the set of data objects, a duration indicator thatidentifies a difference between the timestamp associated with a firstevent in the set of events and the timestamps associated with a lastevent in the set of events, and a timeline marker that identifies thepercentage of the workflow history of the document that corresponds tothe set of data objects.
 14. The computer-readable storage medium ofclaim 8, the operation further comprising: in response to a userselecting an element included in the graphical representation,generating a new graphical representation of a subset of data objectsbased on the set of data objects; and causing the new graphicalrepresentation to be displayed in the graphical user interfaceassociated with the application.
 15. A system for generating andnavigating a graphical representation of a workflow history of anelectronic document, the system comprising: a memory; and a processorcoupled to the memory and configured to: access a plurality of dataobjects stored in a memory, wherein each data object stores informationrelated to a different event generated by an application that isconfigured to modify the document; identify a first time and a secondtime during which the application generates events; select a set of dataobjects from the plurality of data objects, wherein each data object inthe set of data objects includes a timestamp reflecting a time that isequal to either the first time or equal to the second time or falls inbetween the first time and the second time; generate a graphicalrepresentation of the set of data objects; and cause the graphicalrepresentation to be displayed in a graphical user interface associatedwith the application.
 16. The system of claim 15, wherein the step ofidentifying comprises: determining whether at least one data object inthe plurality of data objects is related to a save event; and if atleast one data object is related to a save event, then identifying thefirst time and the second time based on one or more timestamps includedin data objects related to save events in the plurality of data objects,or if no data object is related to a save event, then identifying thefirst time and the second time based on one or more timestamps includedin data objects related to other types of events in the plurality ofdata objects.
 17. The system of claim 15, wherein the step ofidentifying comprises: for each data object in the plurality of dataobjects, calculating an elapsed time between the event associated witheach data object and the next subsequent event generated by theapplication; and identifying the first time and the second time based onone or more timestamps included in the plurality of data objects,wherein the one or more timestamps are selected based on the elapsedtimes calculated for each data object in the plurality of data objects.18. The system of claim 17, wherein the one or more timestamps areselected from the data objects corresponding to the longest elapsedtimes.
 19. The system of claim 15, the processor further configured to:generate a calendar view of the workflow history of the document,wherein one or more thumbnail images that reflect a state of thedocument on a particular day are included in the calendar view; andcause the calendar view to be displayed in the graphical user interfaceassociated with the application.
 20. The system of claim 15, theprocessor further configured to: in response to a user selecting anelement included in the graphical representation, generate a newgraphical representation of a subset of data objects based on the set ofdata objects; and cause the new graphical representation to be displayedin the graphical user interface associated with the application.